textproduct: Rapid City

KEY MESSAGES

- Light snow today, then another chance on Saturday and Sunday.

- Warmer and breezy conditions early next week.

- Unsettled weather may return for the middle of next week.

DISCUSSION

(Today Through Thursday) Issued at 238 AM MST Fri Dec 5 2025

Upper air analysis shows northwest flow continuing from the Pac NW all the way to the Upper Midwest, with a series of embedded waves. The next disturbance to affect the area is crossing central/eastern MT ATTM. Surface analysis shows a broad trough extending from the Dakotas into central Canada, supporting W/NW winds of 10-20kt...and gusts up to 30kt over the NW SD plains. KUDX radar shows light snow moving into portions of NE WY and the northern Black Hills, which is expected to bring an inch or two of snow by 12-14z this morning. The wave will cross the area mid-morning...behind it weak mid-level subsidence to the CWA, ending the best chance for accumulating snowfall. However, steep low level lapse rates will persist through the day, allowing for continued low clouds and flurries/light snow. Any accumulations that does occur for the remainder of the day will be less than an inch. Surface high pressure will move into the Dakotas tonight, bringing a brief dry period before the next round of unsettled weather moves in on Saturday. A surface low will develop ahead of the next wave, along a stalled weak baroclinic zone. Isentropic forcing will increase ahead of the low over south central SD, then quickly move southeast of the CWA. Northerly flow behind the low will reinforce the colder air and will be the focus for precip Saturday and Saturday night. Snow is expected across much of western SD and the northern Black Hills...with southwest SD as the only exception. The highest snow amounts will be over NW SD (1- 3") and the northern Black Hills (1-4"). Lingering snow will be possible on Sunday, especially as models suggest another wave pushing through. Snow amounts will be minimal. Low amplitude dirty ridge then builds over the western CONUS, supporting strong warm air advection. In addition to dry weather, temps should reach into the 40s/low 50s on Monday...then about 5 degrees warmer on Tuesday, along with breezy conditions. Unsettled weather could return toward the middle of next week, but there remains much uncertainty at this time.

AVIATION

(For the 18Z TAFS Through 18Z Saturday) Issued At 1007 AM MST Fri Dec 5 2025

MVFR conditions will continue across northwestern South Dakota through Saturday morning. MVFR cigs and ISOLD -SHSN will end early this afternoon across northeastern Wyoming. Gusty northwest winds with gusts to 35kts are expected this afternoon across the entire area. Another system moves into the forecast area tonight, with areas of MVFR developing early Saturday morning.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.